Long-Term Follow-Up After Direct-Flow Transcatheter Aortic Valve Implantation: A Single Center Experience

Abstract

Aims: Valve degeneration after DirectFlow implantation poses a challenge for valve-in-valve procedures due to its fragile polymeric structure and embolization risk. This study analyzes long-term follow-up of patients who underwent TAVI with DF to understand valve degeneration tendencies. Methods: In this single-center registry, we included all patients who underwent DF implantation in our center. Clinical characteristics and echocardiographic parameters were assessed at baseline and during the latest follow-up. Long-term overall survival was analyzed. Outcome data was compared with a matched cohort of patients who underwent TAVI with other commercial devices during the same period. Results: From 2014 to 2017, 67 patients with significant aortic stenosis were treated with DF; 36 (54%) were male, mean age 83 ± 7 years. Left ventricular ejection fraction was 50 ± 13% with a mean gradient of 46 ± 15 mmHg. Post-procedural echocardiography showed a mean gradient of 16 ± 8 mmHg, markedly higher than the reference group (8 ± 3 mmHg; p < 0.01). This residual gradient showed no progression during follow-up at 20 [9; 39] months (16 ± 9 mmHg; p = 0.52). Overall survival was comparable between DF and the reference group at 12 months (6% vs. 4%, HR 1.37, 95% CI 0.31–6.02) and maximal follow-up of 39 ± 25 months (31% vs. 25%, HR 1.44, 95% CI 0.76–2.73). Conclusions: According to this single center experience, DF devices resulted in higher residual gradients; however, no signs of faster degeneration or worse long-term outcomes were observed compared to other devices.